GPS devices with on-board Bluetooth link directly to a cell phone in the car. The GPS uses the cell phone as a bridge to that phone's wireless Internet service. With the connection established, the GPS device receives instant updates from the phone as it travels. As the position of the car or traffic conditions change, new updates are sent from the phone to the GPS.
GPS Traffic with FM Antenna
In large cities, traffic and weather updates are distributed to GPS devices and other handheld electronics using FM radio waves. A main antenna in the city broadcasts the signal, and repeaters throughout the town carry the signal to areas the frequency may not reach--tunnels, areas with many tall buildings. The GPS users connect a separate antenna to their device and pay a subscription fee to receive the traffic feed. The feed automatically updates itself when conditions change.
GPS Traffic with MSN Direct
Garmin, Pioneer and Nextar GPS devices offer users the option to purchase MSN Direct to receive traffic updates. Found in medium-to-large cities, MSN Direct utilizes 3G wireless networking often used by cell phones to move traffic information to the device. The subscription based service requires an independently powered antenna, which receives traffic data from the Microsoft owned service.
